c_kon/KokursTest2/Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace KokursTest2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            String connstring = "Data Source=DESKTOP-Q8BTJMH;Initial Catalog=konkurs;Integrated Security=True";
            SqlConnection conn = new SqlConnection(connstring);
            conn.Open();
            SqlCommand command = new SqlCommand("Select * From users WHERE login = @login AND password = @password", conn);
            command.Parameters.Add("@login",textBox1.Text);
            command.Parameters.Add("@password", textBox2.Text);
            SqlDataReader reader = null;
            
            try{
                reader = command.ExecuteReader();
                if (reader.HasRows)
                {
                    reader.Read();
                    if (reader["admin"].ToString() == "1")
                    {
                        Form2 fr2 = new Form2();
                        fr2.Show();
                        this.Hide();
                    }
                    if (reader["manager"].ToString() == "1")
                    {
                        Form3 fr3 = new Form3();
                        fr3.Show();
                        this.Hide();
                    }
                }
                else{
                    MessageBox.Show("парроль введен неверно", "авторизация", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }

            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message.ToString(), "", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }

            finally
            {

            }
        }

        private void textBox2_Enter(object sender, EventArgs e)
        {
            if(textBox2.Text == "Введите пароль")
            {
                textBox2.Text = "";
            }
        }

        private void textBox2_Leave(object sender, EventArgs e)
        {
            if (textBox2.Text == "")
            {
                textBox2.Text = "Введите пароль";
            }
        }

        private void textBox1_Enter(object sender, EventArgs e)
        {
            if (textBox1.Text == "Введите логин")
            {
                textBox1.Text = "";
            }
        }

        private void textBox1_Leave(object sender, EventArgs e)
        {
            if (textBox1.Text == "")
            {
                textBox1.Text = "Введите логин";
            }
        }

        private void textBox2_TextChanged(object sender, EventArgs e)
        {

        }
    }
}